499785 第90102538號專利申請案中文說明書修正頁 A7 民國 _ 五、發明説明（1 ) L__________補充 〔發明領域〕 (請先閲讀背面之注意事項再填寫本頁) 本發明大體上係關於相干地（coherently)照明的系 統。更特定地，本發明係關於減少在雷射照明的系統中的 斑點。 〔發明背景〕 相干的光照射一粗糙的表面會產生斑點。來自於該粗 糙的表面反射被稱爲漫射反射。穿過該粗糙表面的透射被 稱爲漫射穿透。在該漫射反射或漫射穿透中，光線散射於 不同的方向上。由該漫射反射或漫射穿透所散射的相干光 線在遠離該粗糙表面的空間中形成一干繞圖案。如果用一 人類的眼睛觀看的話，眼睛將會看到’顆粒狀’圖案之明、 .暗。該顆粒圖案爲斑點。如果一光學系統觀看被該相干光 線所照射的粗糙表面的話，則該光學系統的強度偵測器亦 將會偵測到該斑點。 經濟部智慧財產局員工消費合作社印製 其寄中的一第一種斑點證明（demonstration)設備被 示於第1圖中。該第一種斑點證明設備1包括一第一證明 雷射2, —第一發散透鏡4，及一第一觀看螢幕6，它們 係位在一第一光軸8上。該第一證明雷射2射出一第一雷 射光束1 0。該第一發散透鏡4將該第一雷射束1 〇轉變 爲一發散雷射束1 2。該發散雷射束1 2照射該第一觀看 螢幕6的一第一大的面積1 4。該第一觀看螢幕6漫射地 反射該發散雷射束1 2而產生一干擾圖案。一位在一第二 光軸1 8處的觀察面板1 6與該干擾圖案相交會。該觀察 ^紙張尺度適用中國國家標準（CNS ) A4規格（210 X 29<7公釐） ^ "" -4 - 499785 A7 ___ B7 _ 五、發明説明（2 ) (請先閱讀背面之注意事項再填寫本頁) 面板1 6是在眼睛或該光學系統所聚焦的空間內的觀看區 。應注意的是，該發散透鏡4有助於證明該斑點，但並不 會產生斑點。 ‘ 第2圖爲前技的一典型的斑點1 7的照片，其顯示從 觀.察面板1 6所看到的斑點。從該觀看螢幕6漫射地反射 之發散雷射束1 2的建設性干擾產生該觀察面板1 6上的 亮點。破壞性的干擾則產生亮點之間的暗點。來自於該觀 爛螢幕6之漫射反射具有一隨機的本質，使得亮點與暗點 變化於整個觀察面板1 6上。 .斑點的一項測量値爲對比（C )。對比（百分比）爲 C=l〇〇*IRMS/‘r，其中了爲平均強度，IrMS爲 平均強度附近的平方根強度波動。 經濟部智慧財產局員工消費合作社印製499785 No. 90102538 Patent Application Chinese Specification Revised Page A7 Republic of China _ V. Description of Invention (1) L__________ Supplement [Field of Invention] (Please read the notes on the back before filling this page) This invention is generally related to ( coherently) lighting system. More specifically, the present invention relates to reducing speckle in a system of laser illumination. [Background of the Invention] Irradiation of a rough surface with coherent light causes speckles. The reflection from this rough surface is called diffuse reflection. Transmission through this rough surface is called diffuse penetration. In this diffuse reflection or diffuse penetration, light is scattered in different directions. Coherent light scattered by the diffuse reflection or diffuse penetration forms a dry-wound pattern in a space away from the rough surface. If you look with a human eye, your eyes will see the "grainy" pattern of light and dark. The particle pattern is a spot. If an optical system looks at a rough surface illuminated by the coherent light, the intensity detector of the optical system will also detect the speckle. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. One of the first demonstration equipment in the mail is shown in Figure 1. The first speckle proof device 1 includes a first proof laser 2, a first divergent lens 4, and a first viewing screen 6, which are positioned on a first optical axis 8. The first proof laser 2 emits a first laser beam 10. The first divergent lens 4 transforms the first laser beam 10 into a divergent laser beam 12. The divergent laser beam 12 illuminates a first large area 14 of the first viewing screen 6. The first viewing screen 6 diffusely reflects the divergent laser beam 12 to generate an interference pattern. The observation panel 16 at a position on the second optical axis 18 intersects the interference pattern. This observation ^ The paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 29 < 7 mm) ^ " " -4-499785 A7 ___ B7 _ V. Description of the invention (2) (Please read the note on the back first Please fill in this page again) Panel 16 is the viewing area in the eye or the space focused by the optical system. It should be noted that the divergent lens 4 helps to prove the speckles, but does not produce speckles. ‘Figure 2 is a photograph of a typical spot 17 of the prior art, which shows the spot seen from the viewing panel 16. The constructive interference of the diverging laser beam 12 diffusely reflected from the viewing screen 6 creates a bright spot on the viewing panel 16. Destructive interference creates dark spots between bright spots. The diffuse reflection from the rotten screen 6 has a random nature, so that the bright and dark points change across the entire viewing panel 16. One measure of speckle is contrast (C). The comparison (percentage) is C = 100 * IRMS / 'r, where is the average intensity and IrMS is the square root intensity fluctuation near the average intensity. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs
Goodman 在 '、Some fundamental properties of speckle (J. Opt. Soc. Α., νοΐ. 66, no. 11, Nov. 1976, pp 1145-1150 )中提到斑點可藉由將N個不相關的（uncorrelated)斑 點圖案重疊來加以減少。這可將對比唔低2 / ( N ) 1 / 2 ，如果該等必個不相關的斑點圖案f a;有相同的平均強度 •及對比。如果該等N個不相關的斑點圖案息有不相同的平 均強度或不相同的對比的話，則該斑點減少因數將大於 1 / (. N ) 1 / 2。因此，對於N個不相關的斑點圖案而言 ，1 / ( N ) 1 / ^減少因數是最佳的斑點減少情形。Goodman in ', Some fundamental properties of speckle (J. Opt. Soc. Α., Νοΐ. 66, no. 11, Nov. 1976, pp 1145-1150) mentioned that speckles can be obtained by separating N unrelated ( Uncorrelated) speckle patterns are overlapped to reduce them. This reduces the contrast by 2 / (N) 1/2 if these must be unrelated speckle patterns f a; have the same average intensity • and contrast. If the N unrelated spot patterns have different average intensities or different contrasts, then the spot reduction factor will be greater than 1 / (. N) 1/2. Therefore, for N unrelated speckle patterns, a 1 / (N) 1 // ^ reduction factor is the best speckle reduction scenario.
Goodman進一步教導不相關的斑點圖案可藉由時間， 空間，頻率，或偏振機構來獲得。例如，該空間機構可藉 由一第二證明雷射，其操作的波長與該第一證明雷射2相 本紙張尺度適用中國國家標準( CNS ) A4規格（210X297公釐) "" 一 -5- 499785 A7 B7 五、發明説明（3 ) (請先閲讀背面之注意事項再填寫本頁) 同，及一位在一第三光軸上的第二發散透鏡其照射該第一 觀看螢幕6的第一大的面積1 4，來產生。如果該第一光 軸8及第三光軸被分開一足夠的角度的話，則斑點將可被 減少1 /( 2 ) 1 / 2。角度上的分離是必需的，如果該具 有.第二雷射光束的第二證明雷射被建構成該第一雷射光束 1 〇及該第二雷射光束重疊的話，則斑點將不會被減少， 如果時間，頻率，或偏振機構沒有被使用的話。這是因爲 當角度分離不存在時，該第一證明雷射及該第二證明雷射 會產生相同的斑點圖案，縱使該第一證明雷射2與該第二 證明雷射係不相干（incoherent)。Goodman further teaches that unrelated speckle patterns can be obtained by time, space, frequency, or polarization mechanisms. For example, the space agency can use a second certification laser whose operating wavelength is in accordance with the Chinese standard (CNS) A4 specification (210X297 mm) of the paper size of the first certification laser 2 phase " " a- 5- 499785 A7 B7 V. Description of the invention (3) (Please read the precautions on the back before filling this page) Same, and a second divergent lens on a third optical axis which illuminates the first viewing screen 6 The first large area of 1 to 4 comes. If the first optical axis 8 and the third optical axis are separated by a sufficient angle, the speckles can be reduced by 1 / (2) 1/2. The angular separation is necessary. If the second proof laser with the second laser beam is constructed to form the first laser beam 10 and the second laser beam overlaps, the speckle will not be affected. Reduce if time, frequency, or polarization mechanism is not used. This is because when the angle separation does not exist, the first proof laser and the second proof laser will produce the same speckle pattern, even though the first proof laser 2 and the second proof laser are incoherent ).
Goodman進一步教導該偏振機構可以是一去偏振螢幕 ，其會如隨機第被偏振化的漫射光線般地反射或透射偏振 化的光線。由該去偏振化的螢幕所產生的斑點圖案明顯地 不同，如果從一旋轉中的偏振分析儀來看的話。這顯示照 射該去偏振螢幕之兩個正交的偏振分量產生兩個不相關的 斑點圖案。因此，如果該觀看螢幕6爲一 1 0 0 %的去偏 振螢幕的話，則對比將會.被減少1 / ( 2 ) 1 / 2。 經濟部智慧財產局員工消費合作社印製 用來產生多個斑點圖案之另一此技藝中習知的方法爲 以一擺盪運動1 9的方式來移動該觀看螢幕6，此擺盪運 動1 9.運用Goodman所教導的時間機構。此擺盪運動1 9 典型地沿著一圓圈或一橢圓形軌到繞著該光軸8旋輳。這 造成斑點圖案相對於觀看該觀看螢幕6的眼睛或該光學系 統移動，因而在一段時間內產生多個斑點圖案。雖然在任 一時間點的斑點數量沒有改變，但眼睛會感覺出所產生的 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐·) -6- 499785 A7 料日凭正 __Β7 __補充 五、發明説明（4) (請先閲讀背面之注意事項再填寫本頁) 斑點，如果該擺盪運動的速度是在一門檻速度値之上的話 。該光學系統的強度偵測器會偵測出被斑點被減少，如果 曝光時間夠長以允許斑點圖案移動一明顯的距離的話。 前技中的一第二種斑點證明設備被示於第3圖中。該 斑點證明設備2 0包括一第三證明雷射2 2，一圓柱形發 散透鏡24， 一掃描鏡26，及一第二觀看螢幕28。該 第三證明雷射2 2射出一第三雷射光束30，其耦合至該 圓柱形發散透鏡2 4。該圓柱形發散透鏡2 4將該第三雷 射光束轉換成爲一第二發散雷射光束3 2。該掃描鏡2 6 反射該第二發散雷射光束3 2。因此，該第二雷射發散光 束3 2形成在該第二觀看螢幕2 8上的一線照明3 3。該 掃描鏡2 6以一具有一掃描頻率的掃描運動3 4將該線照 明3 3重復地掃描過該第二觀看螢幕2 8的一部分。因此 ，一第二大的面積被照射。如果眼睛或光學系統觀看該第 二觀看螢幕2 8的話，則眼睛或強度偵測器會偵測到在該 第二觀看螢幕2 8上的照明，如果該掃描頻率夠高的話。 眼睛或強度偵測器亦會偵測到斑點。 經濟部智慧財產局員工消費合作社印製 在許多雷射照明的系統中斑點是一項嚴重的問題。此 問題因爲導因於1 / ( Ν ) 1 / 2減少因數在對比（ contrast )上之一相對慢的減少而更加嚴重。因此，需要 有其它的方法來減少雷射斑點。 〔發明槪要〕 本發明提供一種使用偏振平均來減少雷射斑點的方法 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） ' ~ -7- 499785 A7 B7 五、發明説明（5 ) 與設備。一種偏振光束分光器將一第一偏振化的雷射輸出 分成一第二偏振化的雷射輸出及一第三偏振化的雷射輸出 。多面鏡子在該第二及第三偏振化的雷射輸出之間產生一 光路徑差。該光路徑差至少約爲該第一偏振化的雷射輸出 的相干長度（coherence length )。該第二及第三偏振化的 雷射輸出結合成爲一第四偏振化的雷射輸出。該第四偏振 化的雷射輸出照射一去偏振營幕。如果一*人類的眼睛或一* 具有強度偵測器的光學系統觀看該去偏振螢幕的話，則眼 睛及該強度偵測器將會偵測到斑點被減少。此斑點的減少 是由該.第二及第三偏振化的雷射輸出所產生的不相關的斑 點圖案所造成的平均化效果。 本發明的一第一替代實施例可在該光路徑差不是至少 約爲相干長度之下作用。在佌第一替代實施例中\於一足 夠的頻率下被驅動之一壓電轉換器將一光路徑長度改變， 改變的量至少約爲該第一偏振化的雷射輸出的波長的一半 的偶數倍。將該光路徑改變一足夠的頻率，可提供不相關 的斑點圖案。 一第二替代實施例包括該偏振光束分光器，第一及第 二四分之一波板子，第一及第二鏡子，及壓電轉.換器。該 偏振光.束分光器將該第一偏振化的雷射輸出分成一第五偏 振化的雷射輸出及一第六偏振化的雷射輸出，每一者皆具 有線性的偏振度。該第一及第二四分之一波板子將該直線 的偏振轉變爲圓形的偏振。該第一及第二鏡子反射該第五 偏振化的雷射輸出及該第六偏振化的雷射輸出。該第一及 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐.) (請先閲讀背面之注意事項再填寫本頁) -裝· 訂 經濟部智慧財產局員工消費合作社印製 -8 - 499785 A7 B7 五、發明説明（6 ) (請先閱讀背面之注意事項再填寫本頁) 第H四分之一波板子然後將該圓形的偏振轉變爲直線的偏 振，其爲原來的偏振被旋轉9 〇度。該耦合至該第一鏡子 的壓電轉換器將該第一偏振化的雷射輸出的光路徑長度改 變，其改變量爲爲該第一偏振化的雷射輸出的波長的一半 的偶數倍。該偏振光束分光器將該第五偏振化的雷射輸出 及該第六偏振化的雷射輸出結合爲一第七偏振化的雷射輸 出，其照射該去偏振化的螢幕。藉由將該光路徑改變一足 夠的頻率，眼睛及強度偵測器將會偵測到斑點被減少。 一第三替代實施例將來自於兩個雷射之兩個直交的偏 振雷射輸出加以結合成爲一結合的雷射輸出。該結合的雷 射輸出照射該去偏振螢幕。 一第四替代實施例將該第一雷射輸出以一旋轉頻率加 以旋轉用以形成一轉動偏振。具有此轉動偏振化的第一雷 射輸出照射該去偏振螢幕。 〔圖式簡要說明〕 第1圖爲前技用來證明雷射斑點的設備。 經濟部智慧財產局員工消費合作社印製 第2圖爲該前技之一典型的雷射斑點圖案的照片。 第3圖爲前技用來證明雷射斑點的第二種設備。 第4圖爲本發明之較佳實施例的等角視圖。 第5圖顯示本發明之一偏振光束分光器。 第6圖顯示本發明之一雷射及一半波板子。 第7圖顯示本發明的較佳實施例的平面圖。 第8圖顯示本發明的一第一替代實施例。 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐) -9 -Goodman further teaches that the polarization mechanism can be a depolarized screen that reflects or transmits the polarized light like a randomly polarized diffused light. The speckle patterns produced by this depolarized screen are significantly different if viewed from a rotating polarization analyzer. This shows that irradiating the two orthogonal polarization components of the depolarizing screen produces two uncorrelated speckle patterns. Therefore, if the viewing screen 6 is a 100% depolarized screen, the contrast will be reduced by 1 / (2) 1/2. Another method commonly used in this technique, printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs to produce multiple speckle patterns, is to move the viewing screen 6 in a swing motion 19, this swing motion 19. Use The time agency taught by Goodman. This oscillating motion 19 is typically along a circle or an elliptical track to spin around the optical axis 8. This causes the speckle pattern to move relative to the eye viewing the viewing screen 6 or the optical system, thereby generating a plurality of speckle patterns over a period of time. Although the number of spots has not changed at any point in time, the eyes will feel that the paper size produced is applicable. National National Standard (CNS) A4 Specification (210X297 mm ·) -6- 499785 A7 The material date is positive __Β7 _ _ Supplement V. Description of the invention (4) (Please read the notes on the back before filling this page) Spots, if the speed of the swing motion is above a threshold speed 値. The intensity detector of the optical system will detect that the speckle has been reduced if the exposure time is long enough to allow the speckle pattern to move a significant distance. A second speckle proof device from the prior art is shown in Figure 3. The speckle certification device 20 includes a third certification laser 22, a cylindrical divergent lens 24, a scanning mirror 26, and a second viewing screen 28. The third proof laser 22 emits a third laser beam 30, which is coupled to the cylindrical divergent lens 24. The cylindrical divergent lens 24 converts the third laser beam into a second divergent laser beam 32. The scanning mirror 2 6 reflects the second divergent laser beam 3 2. Therefore, the second laser divergent light beam 32 forms a line of illumination 33 on the second viewing screen 28. The scanning mirror 26 repeatedly scans the line illumination 3 3 through a part of the second viewing screen 28 with a scanning motion 3 4 having a scanning frequency. Therefore, a second largest area is irradiated. If the eye or optical system views the second viewing screen 28, the eye or intensity detector will detect the illumination on the second viewing screen 28 if the scanning frequency is high enough. Eyes or intensity detectors will also detect spots. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Spotting is a serious problem in many laser-illuminated systems. This problem is exacerbated by a relatively slow decrease in one of the contrast factors due to a 1 / (N) 1/2 reduction factor. Therefore, other methods are needed to reduce laser spots. [Invention Summary] The present invention provides a method for reducing laser spots using polarization averaging. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) '~ -7- 499785 A7 B7 V. Description of the invention (5 ) And equipment. A polarized beam splitter divides a first polarized laser output into a second polarized laser output and a third polarized laser output. The polygon mirror creates a light path difference between the second and third polarized laser outputs. The optical path difference is at least about the coherence length of the first polarized laser output. The second and third polarized laser outputs are combined into a fourth polarized laser output. The fourth polarized laser output illuminates a depolarization screen. If a * human eye or * an optical system with an intensity detector views the depolarized screen, the eyes and the intensity detector will detect that the speckle is reduced. This reduction in speckle is an averaging effect caused by uncorrelated speckle patterns produced by the second and third polarized laser outputs. A first alternative embodiment of the present invention may work under conditions where the optical path difference is not at least about a coherence length. In a first alternative embodiment, a piezoelectric transducer that is driven at a sufficient frequency changes a light path length by an amount that is at least about half the wavelength of the first polarized laser output. Even multiples. Changing the light path to a sufficient frequency can provide uncorrelated speckle patterns. A second alternative embodiment includes the polarized beam splitter, first and second quarter-wave plates, first and second mirrors, and a piezoelectric converter. The polarized light beam splitter splits the first polarized laser output into a fifth polarized laser output and a sixth polarized laser output, each of which has a linear degree of polarization. The first and second quarter wave plates convert the linear polarization into a circular polarization. The first and second mirrors reflect the fifth polarized laser output and the sixth polarized laser output. The first and this paper size are applicable. National National Standard (CNS) A4 specification (210X297 mm.) (Please read the precautions on the back before filling out this page) System-8-499785 A7 B7 V. Description of the invention (6) (Please read the precautions on the back before filling out this page) The H quarter wave board then converts the circular polarization to linear polarization, which is The original polarization was rotated 90 degrees. The piezoelectric converter coupled to the first mirror changes the optical path length of the first polarized laser output by an even number multiple of a half of the wavelength of the first polarized laser output. The polarized beam splitter combines the fifth polarized laser output and the sixth polarized laser output into a seventh polarized laser output, which illuminates the depolarized screen. By changing the light path to a sufficient frequency, the eye and intensity detector will detect that the speckle is reduced. A third alternative embodiment combines two orthogonally polarized laser outputs from two lasers into a combined laser output. The combined laser output illuminates the depolarized screen. A fourth alternative embodiment rotates the first laser output at a rotational frequency to form a rotating polarization. The first laser output with this rotational polarization illuminates the depolarized screen. [Brief Description of the Drawings] Figure 1 shows the equipment used by the prior art to prove laser spots. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Figure 2 is a typical laser spot pattern photo of one of the previous techniques. Figure 3 shows the second device used to prove the laser spot by the previous technique. Figure 4 is an isometric view of a preferred embodiment of the present invention. Fig. 5 shows a polarized beam splitter according to the present invention. Figure 6 shows a laser and half-wave board according to the present invention. Figure 7 shows a plan view of a preferred embodiment of the present invention. Fig. 8 shows a first alternative embodiment of the invention. The size of this paper is applicable. National Standard (CNS) A4 (210X297 mm) -9-
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發明説明（ 第9圖顯示本發明的一第二替代 第1 0圖顯示本發明的一第三替 第1 1圖顯不本發明的一第四替 第1 2圖顯示本發明的一第五替 第1 3圖顯示本發明的一第六替 第1 4圖顯示本發明的一第七替 第1 5圖顯示本發明的一第八替 第1 6圖顯示本發明的一第九替 第17圖顯不本發明的一第十替 實施例。 代實施例 代實施例 代實施例 代實施例 代實施例 代實施例 代實施例 代實施例 (請先閲讀背面之注意事項再填寫本頁) -裝· 主要元件對照表 1 •第一斑點證明設備 2 第一證明雷射 4 第一發散透鏡 6 第一觀看螢幕 8 第一烷軸 10 第一雷射束 12 發散雷射束 14 第一大的面積 16 .觀察面板 17 斑點圖案 18 第二光軸 1 9 擺盪運動 2 0 第二斑點證明設備 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公嫠） 訂 經濟部智慧財產局員工消費合作社印製 -10- 499785 A7 B7 經濟部智慧財產局員工消費合作社印製 五、 發明説明 ( 8 2 2 第 二 =32¾ sa 2 4 圓 柱 形 2 6 掃 描 鏡 2 8 第 二 觀 3. 0 第 三 雷 3 2 第 二 發 3 3 線 眧 4 V \\ 明 3 4 掃 描 運 3 6 第 二 大 3 7 較 佳 實 3 8 第 — 雷 4 〇 偏 振 光 4 2 去 偏 振 4 4 光 軸 4 6 第 一 偏 4 8 第 二 偏 4 9 第 二 偏 5 0 第 — 鏡 5 2 第 二 鏡 5 4 第 二 鏡 5 6 第 四 鏡 5 8 第 四 雷 5 9 第 一 部 6 0 第 _. 直 明雷射 發散透鏡 察螢幕 射束 散雷射束 動 的面積 施例 射 束分光器 螢幕 振化的雷射輸出 振化的雷射輸出 振化的雷射輸出 子 子 子 子 射輸出 分視圖 線偏振化的電場 (請先閱讀背面之注意事項再填寫本頁) 裝. 訂 線 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐) -11 - 499785 A7 B7 五、發明説明（9 ) 62 第二直線偏振化的電場 6 4 第三直線偏振化的電場 6 6 偏振光束分光反射器 6 8 斑點減少結構 經濟部智慧財產局員工消費合作社印製 7. 0 第 — 光 路 徑 長 度 7 2 第 二 光 路 徑 長 度 7 4 第 三 光 路 徑 長 度 7 6 第 四 光 路 徑 長 度 7 8 第 五 光 路 徑 長 度 7 9 第 — 部 分 視 圖 8 0 半 波 板 子 8 2 旋 轉 8 3 偏 振 角 度 8 4 第 一 替 代 實 施 例 8 5 第 五 鏡 子 8 6 第 鏡 子 8 8 第 七 鏡 子 9 0 第 — 替 代 實 施 例 9 2 偏 振 保存 光 纖 9 3 第 二 偏 振 化 的 雷 9 4 圓 柱形 發 散 透 鏡 9 6 掃 描 鏡 子 9 8 發 散 雷 射光束 1 0 0 第 二 去 偏 振 螢 — —.--•‘---裝^-- (請先閱讀背面之注意事項再填寫本頁) |線 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐·) -12- 499785 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明説明（10) 102 第一掃描運動 104 第二掃描運動 10 5 第四替代實施例 ‘ 106 壓電轉換器 1.0 8 第一電子訊號 109 第五替代實施例 110 第二電子訊號 1 .1 1 第六替代實施例. 112 第二雷射 1 1 4 第五偏振化的雷射輸出 115 結合的雷射輸出 116 第七替代實施例. 118 第一四分之一波板子 120 第二四分之一波板子 122 第六偏振化的雷射輸出 12 4 第七偏振化的雷射輸出 126 第八偏振化的雷射輸出 130 第八替代實施例 13 2 雙折射結晶體 13 4. 第五直線偏振化的電場 1 3 6 第五直線偏振化的電場 140 第九替代實施例 142 偏振旋轉器 14 4 第三電子訊號 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐) 11.11^---裝------訂-----^線 (請先閲讀背面之注意事項再填寫本頁) -13- 499785 五、發明説明（11 ) 146 第九雷射輸出 150 第十替代實施例 (請先閲讀背面之注意事項再填寫本頁) 15 2 第十偏振化的雷射輸出 15 4 第十一偏振化的雷射輸出 〔最佳實施例詳細說明〕 本發明係根據兩個未相干的（incoherent )、正交地 偏振化的雷射輸出在照射一去偏振螢幕時會產生四個不相 關的（uncorrelated)斑點圖案的事實發現而提出的。 經濟部智慧財產局員工消費合作社印製 本發明的較佳實施例被示於第4圖中。該較佳的實施 例3 7包括一第一雷射3 8 , —半波板子8 0，一去偏振 光束分光器4 0，及該去偏振螢幕4 2，它們係位在一光 軸4 4上。該具有一相干長度之第一雷射3 8發出一第一 偏振化的雷射輸出4 6其爲一直線地偏振化的準直光束。 該第一偏振化的雷射輸出4 6係耦合至該偏振光束分光器 4 0。該偏振光束分光器4 〇將該第一偏振化的雷射輸出 4 6分成一第二偏振化的雷射輸出4 8及一第三偏振化的 雷射輸出4 9。該第三偏振化的雷射輸出4 9持續沿著該 光軸4 4前進。該第二偏振化的雷射輸出4 8被該第一鏡 子5 0，一第二鏡子5 2，一第三鏡子5 4及一第四鏡子 56所反射。該第一，第二，第三及第四鏡子50, 52 ，5 4及5 6界定一光線導向器。熟悉此技藝者可很快地 瞭解到較多或較少的鏡子亦可被用來達成本發明的目的。 在被該第四鏡子5 6所反射之後，該第二偏振化的雷 本紙張尺度適用中國國家標準（CNS ) A4規格（2丨0 X297公釐） -14- 499785 A7 B7 五、發明説明（12) 射輸出4 8被該偏振光束分光器5 6所反射，該分光器將 該第二偏振化的雷射輸出4 8及該第三偏振化的雷射輸出 4 9結合成爲一第四偏振化的雷射輸出5 8。藉由將該第 二偏振化的雷射輸出傳送通過該光線導向器，該第二偏振 化的雷射輸出4 8已相對於該第三偏振化的雷射輸出4 9 偏移一光路徑差。該第四偏振化的雷射輸出5 8然後被耦 合至該去偏振螢幕4 2。該去偏振螢幕4 2將該第四雷射 輸出如隨機偏振化的漫射光線般地加以反射或透射。如果 該去偏振螢幕4 2反射該第四雷.射輸出5 8的話，則該去 偏振螢幕4 2’包含一漫射反射螢幕。如果該去偏陣螢幕 42透射該第四雷射輸出58的話，則該去偏振螢幕42 包含一漫射穿透螢幕。如果該光路徑差至少爲一足夠的距 離的話，則觀看該去偏振螢幕4 2之一光學系統的強度偵 測器或眼睛可看到斑.點被減少。 最好是，該足夠的距離爲相干長度。或者，該足夠的 距離小於該相干長度，但斑點的減少將會少於該足夠的距 離爲至少該相干長度的情形。 第4圖中的第一部分視圖5 9被示於第5圖中。該第 一部分視圖5 9包括該偏振光束分光器4 0，第一及第二 偏振化的雷射輸出4 6及4 8，及該第四雷射輸出5 8。 該第一偏振化的雷射輸出4 6具有一第一直線的偏振E ( 電）場6 0。該第一直線的偏振E場6 0爲一第二直線的 偏振E.(電）場6 2與一第三直線的偏振E (電）場6 4 的結合，它們爲該第一直線的偏振E (電）場6 〇的兩個 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐) —j--^---·丨裝^-- (請先閱讀背面之注意事項再填寫本頁) 、τ 線 經濟部智慧財產局員工消費合作社印製 -15- 499785 A7 B7 五、發明説明（13) — ―^--^---―裝-- (請先閲讀背面之注意事項再填寫本頁) 直交的偏振。最好是，該第二直線的偏振E (電）場6 2 及該第三直線的偏振E (電）場6 4具有相同的振幅。在 較佳的實施例3 7 (第4圖）>，相等的振幅係藉由繞著 該光軸4 4旋轉半波板子8 0而獲得的。 參照第5圖，該第二直線的偏振E (電）場6 2爲垂 直的及該第三直線的偏振E (電）場6 4爲水平的。該偏 振光束分光器4 0從一偏振光束分光反射器6 6反射具有 該第二直線的偏振E (電）場6 2的第一偏振化的雷射輸 出4 6，同時讓具有該第三直線的偏振E (電）場6 .4的 第一偏振化的雷射輸出通過該偏振光束分光反射器6 6。 因此，該第二偏振化的雷射輸出4 8爲該具有第二直線的 偏振E (電）場6 2的第一偏振化的雷射輸出4 6。而且 ，該第三偏振化的雷射輸出4 9爲該具有第三直線的偏振 E (電）場.6 4的第一偏振化的雷射輸出4 6。 經濟部智慧財產局員工消費合作社印製 該第一偏振,化的雷射輸出4 6及第二偏振化的雷射輸 出4 9界定一相對於該偏振光束分光反射器6 6的入射平 面。在光學的習慣上將該第二直線的偏振E (電）場6 2 成爲一 s —偏振及將該第三直線的偏振E (電）場6 4稱 爲P -偏振，其中s代表與入射平面垂直及p代表與該入 射平面平行。對於熟悉此技藝者而言很明顯的是，該第一 直線的偏振E (電）場6 0可被一圓形偏振化的E場所取 代。 第4葡的一第二部分視圖7 9被示於第.6圖中。該第 二部分視圖7 9包括該第一雷射3 8及該半波板子.8 0。 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐.) -16- 經濟/部智慧財產局員工消費合作社印製 499785 A7 B7 五、發明説明（14) — ~' ： 該半波板子8 〇繞著該光軸4 4的旋轉8 2將該第一直線 的偏振E (電）場6 〇轉動使得一偏振角度8 3被調整。 該旋轉8 2被用來讓該第二直線的偏振£ (電）場6 2與 δ亥第二直線的偏振e (電）場6 4相等。對於熟悉此技藝 者而言很明顯的是，該半波板子8 〇可被取消，因爲該第 一及第三直線的偏振Ε (電）場6 2及6 4的振幅可藉由 旋轉該第一雷射3 8而相等。 較佳實施例3 7的一平面圖被示於第7圖中，其包括 該偏振光束分光器4 0及第一，第二，第三及第四鏡子 5 0，. 5 2，‘ 5 4及5 6，它們被界定爲一斑點減少結構 δ 8。該偏振光束分光器4 0將該第一偏振化的雷射輸出 4 6分成該第二偏振化的雷射輸出4 8及該第三偏振化的 .雷射輸出4 9。該第二偏振化的雷射輸出4 8沿著一第一 光路徑長度7 0從該偏振光束分光反射器6 6前進至該第 一鏡子5 0。該第二偏振化的雷射輸出4 8沿著一第二光 路徑長度7 2從該第一鏡子5 0前進至該第二鏡子5 2。 該第二偏振化的雷射輸出4 8沿著一第三光路徑長度74 從該第二鏡子5 2前進至該第三鏡子5 4。該第二偏振化 的雷射輸出4 8沿著一第四光路徑長度7 6從該第三鏡子 5 4前進至該第四鏡子5 6。該第二偏振化的雷射輸出 4 8沿著一第五光路徑長度7 8從該第四鏡子5 6前進至 該偏振光束分光反射器6 6。該第一，第二，第三，第四 及第五光路徑長度70, 7 2. , 74，76及78,其每 一者都是幾何長度乘上折射率的總合。 本紙張尺度適用中國國家標準（CNS ) A4規格（210 X 297公f ~ -17. I ----^----裝------訂-----線 (請先閲讀背面之注意事項再填寫本頁) 499785 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明説明（15) 該第一，第二，第三，第四及第五光路徑長度7〇, 7 2，74，7 6及7 8界定該光路徑差。對於熟悉此技 藝者而言很明顯的是，該第二，第三，第四光路徑長度 72， 74， 76可，但不一定要，位在一由該第一偏振 化的雷射輸出4 6，第一光路徑長度7 0及第五光路徑長 度7 8所界定的一平面上。 在該第二偏振化的雷射輸出4 8經過該光路徑差之後 ，該偏振光束分光反射器6 6會反射該第二偏振化的雷射 輸出4 8使得該第二偏振化的雷射輸出4 8及該第三偏振 化的雷射輸出4 9相結合而形成該第四雷射輸出5 8。該 第四雷射輸出5 8照射該去偏振螢幕4 2。最好是，該光 路徑差等於或大於該第一雷射3 8的相干長度。其結果爲 ，由該P -偏振及s -偏振所產生斑點爲非相干的。或者 ，該光路徑差小於該相干長度，但這所造成的結果爲斑點 的減少較少因爲p -偏振及S -偏振係部分相干。 該去偏振螢幕4 2從該p -偏振產生不相關的第一及 第二斑點圖案。該去偏振螢幕4 2亦從該s —偏振產生不 相關的第三及第四斑點圖案。對於至少爲該相干長度的該 光路徑差而言，該第一，第二，第三及第四斑點圖案係不 相關的·，因爲P —偏振及S -偏振是非相干的。因此，斑 點減少結構6 8及該去偏振螢幕4 2產生總數爲4個的不 相關的斑點圖案。斑點理論上被減少1 /( 4 ) 1 / 2 = 1 / 2的斑點減少因數。1 / 2的斑點減少因數爲去偏振 螢幕4 2 (其貢獻1 /( 2 ) 1 / 2的因數）與斑點減少結 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐·） ^ ^ , 〆 , 裝 ' . 訂 ^ 線 (請先閲讀背面之注意事項再填寫本頁) • 18 )785 A7 B7 五、發明説明（16) 構6 8 (其賃獻1 / ( 2 ) 1 / 2的因數）的結合。 (請先閲讀背面之注意事項再填寫本頁) 對於小於相干長度的光路徑差而言，在第一與第三斑 點圖案之間，及在第二與第四斑點圖案之間有一部分的相 千性，因爲該P -偏振及s -偏振係部分相干。在此例子 中.，斑點減少因數將介於1 / ( 2 ) 1 / 2與1 / 2之間。 本發明的一第一替代實施例被示於第8圖中。該第一 替代實施例8 4包括一第五鏡子8 5，一第六鏡子8 6及 〜第七鏡子88。該第五，第六，及第七鏡子85, 86 ，及8 8形成該光線導向器，其提供該第二偏振化的雷射 輸出4 8之光路徑差。 本發明的一第二替代實施例被示於第9圖中。該第一 替代實施例9 0包括一偏振保存光纖9 2其形成提供該第 二偏振化的雷射輸出4 8之光路徑差的光線導向器。 經濟部智慧財產局員工消費合作社印製 本發明的一第三替代實施例被示於第1 0圖中。該第 一替代實施例9 3包括該第一雷射3 8 ,該半波板子8 0 ，該斑點減少結構6 8，一圓柱形發散透鏡9 4，一掃描 鏡9 6，及一第二去偏振螢幕1 0 0。該圓柱形發散透鏡 將該第四雷射輸出5 8轉變爲一發散的雷射光束9 8。該 掃描鏡將該發散的雷射光束9 8反射至該去偏振螢幕4 2 上，並在該去偏振螢幕4 2上形成一線照明。該掃描鏡以 —鋸齒狀的掃描運動將該線照明掃描通過該第二去偏振螢 幕1 00。該鋸齒狀的掃描運動具有兩個分量。在一第一 掃描運動1 0 2中，該掃描鏡將該線照明9 8掃描通過該 第二去偏振螢幕1 〇 〇。在一第二掃描運動1 04.中，該 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐‘) 499785 經濟部智慧財產局員工消費合作社印製 A7 五、發明説明（17) 掃描鏡回至該第一掃描運動1 0 2的起點。該第二掃描運 動1 〇 4比第一掃描運動1 〇 2快很多。該鋸碜狀掃描運 動父替地重復該第一掃描運動1 〇 2及第二掃描運動 1 〇 4 °因此，該第一掃描運動1 〇 2提供該第二去偏振 m‘幕1 0 0主要的照明。對於熟悉此技藝者而言很明顯的 是，其它的掃描運動及訊序亦可被用來照射該第二去偏振 螢幕1 0 0 〇 在此第三替代實施例9 3中，斑點係被四個不相關的 斑點圖案所減少。此四個不相關的斑點圖案是由該第二去 偏振螢幕Γ 〇 〇與該光路徑差（其爲斑點減少結構6 8所 提供的）的結合所造成的。 如果該第一雷射3 8具有一長的相干長度的話，則讓 該光路倥差等於或大於第一雷射3 8的相干長度是很困難 或不實際的。本發明之考慮長的相干長度之一第四替代實 施例被示於第1 1圖中。此第四實施例1 〇 5加入一壓電 轉換器1 0 6至較佳實施例中。在此第四替代實施例 1 0 5中，該壓電轉換器1 〇6被耦合至該第四鏡子5 6 。對於熟悉此技藝者而言很明顯的是，該壓電轉換器 1 0 6被耦合至第一，第二或第三鏡子5 0 , 5 2或5 4 ，或該壓電轉換器1 0 6被耦合至多個鏡子。 在此第四替代實施例1 0 5中，該壓電轉換器1 〇 6 移動該第四鏡子5 6使得該光路徑差被改變一振幅。藉以 將該光路徑差改變一足夠的頻率，該第三及第四斑點圖案 會相對於該第一及第二斑點圖案偏移，眼睛及強度偵測器 本紙張尺度適用中.國國家標準（CMS ) A4規格（210X297公釐.） I . ； A_w 裝 訂 線 (請先閱讀背面之注意事項再填寫本頁) -20- 499785 A7 B7 五、發明説明（18) {請先閲讀背面之注意事項再填寫本頁} 因而可偵測到被斑點被減少。此足夠的頻率是由眼睛或強 度偵測器的一集成時間（integration time )來決定。一第 一電子訊號1 0 8驅動該壓電轉換器9 4。該第一電子訊 號1 0 8最好是在該足夠頻率下被驅動的一振盪電壓。對 於熟悉此技藝者而言很明顯的是，其它的電子訊號亦可被 用來驅動該壓電轉換器1 0 6，包括一隨機的波動訊號。 最好是，該電子訊號1 0 8爲一方形波訊號。對於〜 方形波而言，振幅最好是該第一偏振化的雷射輸出4 6的 一半波長的偶數倍。或者，該電子訊號1 0 8爲一非方形 波訊號，如一正弦波。對於非方形波訊號而言，振幅最好 至少是該第一偏振化的雷射輸出4 6的一半波長。 經濟部智慧財產局員工消費合作社印製 本發明的一第五替代實施例被示於第1 2圖中。第五 替代實施例1 0 9加入一壓電轉換器1 0 6至第三替代實 施例9 3中。在此第五替代實施例1 0 9中，該光路徑差 不一定要等於或大於該相干長度。在此第五替代實施例 1 0 9中，該壓電轉換器1 0 6改變該光路徑差，改變的 量爲該第一偏振化的雷射輸出4 6的一半波長的偶數倍。 在此第五替代實施例1 0 9中，一第二電子訊號1 1 0驅 動該壓電轉換器1 0 6。該第二電子訊號1 1 0爲一方形 波電壓.，其具有一第一電壓水準，一第二電壓水準，及一 方形波周期。第一電壓水準與第二電壓水準之間的一差値 將該光路徑差偏移半波長的偶數倍。該方形波周期爲該第 一電壓水準及該第二電壓水診的一個循環。. 在此第五替代實施例1 0 9中，該第一掃描運動 本紙張尺度適用中.國國家標準（CNS ) A4規格（210 X297公董) -21 - 499785 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明説明（19) 1 0 2及第一掃描運動1 〇 4被界定爲一掃描周期。對於 一第一掃描周期而言，該方形波電壓具有該第一電壓水準 。對於一緊接在該第一掃描周期之後的第二掃描周期而言 ，該方形波電壓具有該第二電壓水準。對於後續的掃描而 言，該方形波周期對應於兩個掃描周期，使得對於一第三 掃描周期而言，方形波電壓具有該第一電壓水準，及對於 一弟四掃描周期而S，方形波電壓具有該第二電壓水準。 因此，該第三及第四不相關的斑點圖案在每一掃描周期對 中都會相對於該第一及第二不柑關的斑點圖案偏移。斑點 因該去偏振螢幕1 0 0 ,鋸齒狀掃描運動，及第三及第四 不相關的斑點圖案的偏移的綜合影響而被減少.。 本發明的一第六替代實施例被示於第1 3圖中。第六 替代實施例1 1 1加入一第二雷射1 1 2至該第一雷射 3 8 ,該偏振光束分光器4 0，及該去偏振螢幕4 2。該 第一雷射3 8被建構成該第一偏振化的雷射輸出4 6具有 一相對於該偏振光束分光器6 6而被定向於一 p —偏振上 的電場。該第二雷射輸出1 1 2被建構成該第五偏振化的 雷射輸出11 4具有一相對於該偏振光束分光器6 6而被 定向於一 s -偏振上的電場。該偏振光束分光器6 6包括 多層化的介電質其將s -偏振反射並讓p —偏振透射過。 該第一偏振化的雷射輸出4 6通過該偏振光束分光器6 6 。該第五偏振化的雷射輸出114被該偏振光束分光器 θ Θ反射。 在此第六替代實施例1 1 1中，該第一偏振化的雷射 (請先閱讀背面之注意事項再填寫本頁) -裝· 、τ -線 本紙張尺度適用中.國國家標準（CNS ) A4規格（2 Η) X 297公釐) -22- 499785 ，一抑丨.,、丨_丨，•她祕. A7 B7 五、發明説明（20) 輸出4 6與該第五偏振化的雷射輸出1 1 4結合形成一結 合的雷射輸出1 1 5。該結合的雷射輸出1 1 5照射該去 偏振螢幕4 2。因爲該第一雷射3 8及第二雷射1 1 2彼 此係非相干，所以當該結合的雷射輸出1 1 5照射在該去 偏振螢幕4 2上時會產生四個不相關的斑點圖案。對於熟 悉此技藝者而言很明顯的是，該偏振光束分光器4 0可用 一功能與該該偏振光束分光器6 6的多層化的介電質相似 的裝置所取代。 本發明的一第七替代實施例被示於第1 4圖中。.第七 替代實施例1 1 6包括該第一雷射3 8，該半波板子8 0 ，該偏振光束分光器4 0，第一及第二鏡子5 0及5 2 , 該去偏振螢幕42，該壓電轉換器106,該第一電子訊 號1 0 8，及該第一及第二四分之一波板子1 1 8及 1 2 0。該偏振光束分光器4 0將該第一偏振化的雷射輸 出4 6分成第六及第七偏振化的雷射輸出1 2 2及1 2 .4 其分別具有p -偏振及s -偏振。該第一及第二四分之一 波板子1 1 8及1 2 0具有第一及第二光軸，其分別相對 於第六及第七偏振化的雷射輸出1 2 2及1 2 4的p -偏 振及s -偏振被轉4 5度。該第一及第二四分之一波板子 1 1 8.及1 2 0分別將第六及第七偏振化的雷射輸出 1 2 2及1 2 4的P -偏振及s -偏振轉變爲圓形偏振。 被該第一電子訊號1 〇 8所驅動的該壓電轉換器1 0 6將 該第六偏振化的雷射輸出1 2 2的一第六光路徑長度改變 ，其改變量爲振幅。該第一電子訊號1 0 8最好是在該足 本紙張尺度適用中國國家標準（CNS ) A4規格{ 210X297公釐) (請先閲讀背面之注意事項再填寫本頁) •裝.Description of the invention (FIG. 9 shows a second alternative of the present invention. FIG. 10 shows a third alternative of the present invention. FIG. 11 shows a fourth alternative of the present invention. FIG. 12 shows a fifth alternative of the present invention. FIG. 13 shows a sixth replacement of the present invention. FIG. 14 shows a seventh replacement of the present invention. FIG. 15 shows an eighth replacement of the present invention. FIG. 16 shows a ninth replacement of the present invention. Figure 17 shows a tenth alternative embodiment of the present invention. Example Example Example Example Example Example Example Example (Please read the notes on the back before filling this page )-Installation · Main component comparison table 1 • First spot certification device 2 First certification laser 4 First divergent lens 6 First viewing screen 8 First alkane axis 10 First laser beam 12 Divergent laser beam 14 First Large area 16. Observation panel 17 Spot pattern 18 Second optical axis 1 9 Swaying motion 2 0 Second spot proves that the paper size is applicable. National Standard (CNS) A4 size (210X297 public money) Order of Intellectual Property of the Ministry of Economic Affairs Printed by the Bureau's Consumer Cooperatives-10-499785 A7 B7 Ministry of Economic Affairs Printed by the Consumer Cooperative of the Property Bureau V. Invention Description (8 2 2 Second = 32¾ sa 2 4 Cylindrical 2 6 Scanning Mirror 2 8 Second View 3. 0 Third Thunder 3 2 Second Round 3 3 Line 眧 4 V \\ Ming 3 4 Scanning 3 6 Second Big 3 7 Better Real 3 8 First-Lei 4 〇 Polarized Light 4 2 Depolarized 4 4 Optical Axis 4 6 First Offset 4 8 Second Offset 4 9 Second Offset 5 0 No.-Mirror 5 2 Second Mirror 5 4 Second Mirror 5 6 Fourth Mirror 5 8 Fourth Lightning 5 9 First Part 6 0 _. Straight Laser Divergence Lens Checks the area of the screen beam divergent laser beam movement Example Beam Splitter Screen Vibrated Laser Output Vibrated Laser Output Vibrated Laser Output Sub-Sub-Sub-Emitted Output Field View Linearly Polarized Electric Field ) Binding. The size of the paper is applicable. National Standard (CNS) A4 (210X297 mm) -11-499785 A7 B7 V. Description of the invention (9) 62 Second linearly polarized electric field 6 4 Third straight Polarized electric field 6 6 polarized beam splitter reflector 6 8 spots Reduced printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Structural Economy 7. 0th-optical path length 7 2 second optical path length 7 4 third optical path length 7 6 fourth optical path length 7 8 fifth optical path length 7 9 Part — partial view 8 0 half wave plate 8 2 rotation 8 3 polarization angle 8 4 first alternative embodiment 8 5 fifth mirror 8 6 first mirror 8 8 seventh mirror 9 0 — alternative embodiment 9 2 polarization preserving fiber 9 3 The second polarized light 9 4 The cylindrical divergent lens 9 6 The scanning mirror 9 8 The divergent laser beam 1 0 0 The second depolarized fluorescence — —.-- • '--- install ^-(Please read the back first Please note this page before filling in this page) | The paper size of the paper is applicable. National Standard (CNS) A4 (210X297 mm ·) -12- 499785 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (10) 102 first scanning motion 104 second scanning motion 10 5 fourth alternative embodiment '106 piezoelectric transducer 1.0 8 Electronic signal 109 Fifth alternative embodiment 110 Second electronic signal 1.1 .1 1 Sixth alternative embodiment. 112 Second laser 1 1 4 Fifth polarized laser output 115 Combined laser output 116 Seventh alternative implementation Example. 118 First quarter wave board 120 Second quarter wave board 122 Sixth polarized laser output 12 4 Seventh polarized laser output 126 Eighth polarized laser output 130 No. Eight alternative embodiments 13 2 Birefringent crystal 13 4. Fifth linearly polarized electric field 1 3 6 Fifth linearly polarized electric field 140 Ninth alternative embodiment 142 Polarization rotator 14 4 Third electronic signal .National standard (CNS) A4 specification (210X297 mm) 11.11 ^ --- install ------ order ----- ^ line (please read the precautions on the back before filling this page) -13- 499785 V. Description of the invention (11) 146 Ninth laser output 150 Tenth alternative embodiment (please read the precautions on the back before filling this page) 15 2 Tenth polarized laser output 15 4 Eleventh polarized Laser output [detailed description of the preferred embodiment] The present invention is based on two non-phase The (incoherent), orthogonally polarized output of laser fact produce four uncorrelated (uncorrelated) speckle pattern discovery made when irradiated with a depolarizing screen. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A preferred embodiment of the present invention is shown in FIG. The preferred embodiment 37 includes a first laser 3 8, a half-wave plate 80, a depolarizing beam splitter 40, and the depolarizing screen 4 2, which are positioned on an optical axis 4 4 on. The first laser 3 8 with a coherent length emits a first polarized laser output 4 6 which is a linearly polarized collimated beam. The first polarized laser output 4 6 is coupled to the polarized beam splitter 40. The polarized beam splitter 40 divides the first polarized laser output 46 into a second polarized laser output 48 and a third polarized laser output 49. The third polarized laser output 49 continues along the optical axis 44. The second polarized laser output 48 is reflected by the first mirror 50, a second mirror 52, a third mirror 54, and a fourth mirror 56. The first, second, third and fourth mirrors 50, 52, 54 and 56 define a light guide. Those skilled in the art will quickly understand that more or fewer mirrors can also be used to achieve the purpose of the invention. After being reflected by the fourth mirror 56, the size of the second polarized paper is applicable to the Chinese National Standard (CNS) A4 (2 丨 0 X297 mm) -14- 499785 A7 B7 V. Description of the invention ( 12) The radiation output 4 8 is reflected by the polarized beam splitter 56, which combines the second polarized laser output 4 8 and the third polarized laser output 4 9 into a fourth polarization化 的 LASER OUTPUT 5 8. By transmitting the second polarized laser output through the light guide, the second polarized laser output 4 8 has been shifted by an optical path difference from the third polarized laser output 4 9 . The fourth polarized laser output 5 8 is then coupled to the depolarized screen 4 2. The depolarizing screen 42 reflects or transmits the fourth laser output like a randomly polarized diffused light. If the depolarizing screen 4 2 reflects the fourth laser output 5 8, the depolarizing screen 4 2 'includes a diffuse reflection screen. If the depolarized array screen 42 transmits the fourth laser output 58, the depolarized screen 42 includes a diffused penetrating screen. If the light path difference is at least a sufficient distance, the intensity detector of the optical system of one of the depolarizing screens 42 or the eye can see the spots. The spots are reduced. Preferably, the sufficient distance is a coherence length. Alternatively, the sufficient distance is less than the coherence length, but the reduction in spots will be less than the case where the sufficient distance is at least the coherence length. A first partial view 59 in FIG. 4 is shown in FIG. 5. The first partial view 59 includes the polarized beam splitter 40, the first and second polarized laser outputs 46 and 48, and the fourth laser output 58. The first polarized laser output 46 has a first linearly polarized E (electrical) field 60. The polarization E field 60 of the first straight line is the polarization E (electrical) field 62 of a second straight line and the polarization E (electrical) field 6 4 of a third straight line, which are the polarization E (electrical) field of the first straight line ( Electricity) The two paper sizes of the field 60 are applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) —j-^ --- · 丨 installation ^-(Please read the precautions on the back before filling in this Page), printed by the Consumer Cooperatives of Intellectual Property Bureau of the Ministry of Economic Affairs -15-499785 A7 B7 V. Description of the invention (13) — ― ^-^ ------- install-(Please read the precautions on the back before Fill out this page) Orthogonal polarization. Preferably, the polarization E (electrical) field 62 of the second straight line and the polarization E (electrical) field 64 of the third straight line have the same amplitude. In the preferred embodiment 37 (Fig. 4) >, the equal amplitude is obtained by rotating the half-wave plate 80 around the optical axis 44. Referring to Fig. 5, the polarization E (electrical) field 62 of the second straight line is vertical and the polarization E (electrical) field 64 of the third straight line is horizontal. The polarized beam splitter 40 reflects a first polarized laser output 4 6 having a polarized E (electrical) field 62 of the second straight line from a polarized beam splitter reflector 6 6 while letting the third straight line The first polarized laser output of the polarized E (electrical) field 6.4 passes through the polarized beam splitter reflector 6 6. Therefore, the second polarized laser output 48 is the first polarized laser output 46 of the polarization E (electrical) field 62 with a second straight line. Moreover, the third polarized laser output 49 is the first polarized laser output 46 with the third linear polarization E (electrical) field .64. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs The first polarized laser output 46 and the second polarized laser output 4 9 define an incident plane with respect to the polarized beam splitter reflector 6 6. In the optical habit, the polarization E (electrical) field 6 2 of the second straight line becomes an s-polarization and the polarization E (electrical) field 6 4 of the third straight line is referred to as P-polarization, where s represents the incidence The plane perpendicular and p represent parallel to the incident plane. It is obvious to those skilled in the art that the first linearly polarized E (electrical) field 60 can be replaced by a circularly polarized E field. A second partial view 79 of the fourth Portuguese is shown in Fig. 6. The second partial view 799 includes the first laser 38 and the half-wave board .80. This paper is applicable in China. National Standard (CNS) A4 specification (210X297 mm.) -16- Printed by the Consumers 'Cooperative of the Intellectual Property Bureau of the Ministry of Economy / Ministry 499785 A7 B7 V. Description of the invention (14) — ~': This half The rotation of the wave plate 80 around the optical axis 44 is to rotate the polarization E (electrical) field 60 of the first straight line so that a polarization angle 83 is adjusted. The rotation 8 2 is used to make the polarization (electrical) field 62 of the second straight line equal to the polarization e (electrical) field 64 of the second straight line. It is obvious to those skilled in the art that the half-wave plate 80 can be eliminated because the amplitudes of the first and third linear polarization E (electrical) fields 6 2 and 6 4 can be rotated by rotating the first A laser is equal to 3 8. A plan view of the preferred embodiment 37 is shown in FIG. 7, which includes the polarized beam splitter 40 and the first, second, third, and fourth mirrors 50, 5, 2, 5 and 5 5 6 They are defined as a speckle reduction structure δ 8. The polarized beam splitter 40 divides the first polarized laser output 46 into the second polarized laser output 48 and the third polarized .laser output 49. The second polarized laser output 4 8 advances from the polarized beam splitter reflector 6 6 to the first mirror 50 along a first optical path length 70. The second polarized laser output 4 8 advances from the first mirror 50 to the second mirror 52 along a second light path length 72. The second polarized laser output 48 is advanced from the second mirror 52 to the third mirror 54 along a third optical path length 74. The second polarized laser output 4 8 advances from the third mirror 54 to the fourth mirror 56 along a fourth optical path length 7 6. The second polarized laser output 4 8 advances from the fourth mirror 56 to the polarized beam splitter reflector 6 6 along a fifth optical path length 7 8. The first, second, third, fourth, and fifth optical path lengths 70, 7 2., 74, 76, and 78, each of which is the sum of the geometric length times the refractive index. This paper size applies to China National Standard (CNS) A4 specification (210 X 297 male f ~ -17. I ---- ^ ---- installation ------ order ----- line (please read first Note on the back, please fill in this page again) 499785 Printed by the Consumer Property Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Invention Description (15) The length of the first, second, third, fourth and fifth light paths is 70, 7 2, 74, 7 6 and 7 8 define the light path difference. It is obvious to those skilled in the art that the second, third, and fourth light path lengths 72, 74, 76 are possible, but not necessarily Essentially, it is located on a plane defined by the first polarized laser output 46, the first optical path length 70 and the fifth optical path length 78. At the second polarized laser output After passing through the optical path difference, the polarized beam splitter reflector 6 6 reflects the second polarized laser output 4 8 such that the second polarized laser output 4 8 and the third polarized laser output The radiation output 4 9 is combined to form the fourth laser output 58. The fourth laser output 5 8 illuminates the depolarizing screen 42. Preferably, the optical path difference is equal to or greater than Coherence length of the first laser 38. As a result, the spots generated by the P-polarization and s-polarization are non-coherent. Or, the difference in optical path is smaller than the coherence length, but the result is a speckle The reduction is less because the p-polarization and S-polarization are partially coherent. The depolarizing screen 42 produces uncorrelated first and second speckle patterns from the p-polarization. The depolarizing screen 42 also deviates from the s — The polarization produces irrelevant third and fourth speckle patterns. For the optical path difference of at least the coherence length, the first, second, third and fourth speckle patterns are irrelevant, because P — Polarization and S-polarization are non-coherent. Therefore, the speckle reduction structure 6 8 and the depolarizing screen 4 2 produce a total of 4 unrelated speckle patterns. The speckle is theoretically reduced by 1 / (4) 1/2 = 1 The speckle reduction factor of 1/2. The speckle reduction factor of 1/2 is the depolarizing screen 4 2 (which contributes a factor of 1 / (2) 1/2) and the speckle reduction paper size is applicable. National National Standard (CNS) A4 size (210X297mm ·) ^ ^, 〆, installed '. Order ^ line (please first Note read back surface of the page and then fill) • 18) 785 A7 B7 V. invention is described in (16) structure 68 (which offered lease 1 / (2) a factor 1/2) binding. (Please read the precautions on the back before filling out this page.) For light path differences less than the coherence length, there is a portion of the phase between the first and third spot patterns and between the second and fourth spot patterns This is because the P-polarization and s-polarization are partially coherent. In this example, the speckle reduction factor will be between 1 / (2) 1/2 and 1/2. A first alternative embodiment of the invention is shown in FIG. The first alternative embodiment 84 includes a fifth mirror 85, a sixth mirror 86, and a seventh mirror 88. The fifth, sixth, and seventh mirrors 85, 86, and 88 form the light guide, which provides the light path difference of the second polarized laser output 48. A second alternative embodiment of the invention is shown in FIG. The first alternative embodiment 90 includes a polarization preserving optical fiber 92 which forms a light guide with a light path difference providing the second polarized laser output 48. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A third alternative embodiment of the present invention is shown in FIG. The first alternative embodiment 93 includes the first laser 3 8, the half-wave plate 80, the speckle reduction structure 6 8, a cylindrical divergent lens 9 4, a scanning mirror 96, and a second lens. Polarized screen 1 0 0. The cylindrical divergent lens transforms the fourth laser output 58 into a divergent laser beam 98. The scanning mirror reflects the divergent laser beam 98 onto the depolarizing screen 42, and forms a line of illumination on the depolarizing screen 42. The scanning mirror scans the line illumination through the second depolarizing screen 100 in a zigzag scanning motion. This jagged scanning motion has two components. In a first scanning motion 102, the scanning mirror scans the line illumination 98 through the second depolarizing screen 100. In a second scanning campaign 1 04., this paper size is applicable. National Standard (CNS) A4 (210X297 mm ') 499785 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 V. Invention Description (17 ) The scanning mirror returns to the starting point of the first scanning movement 102. This second scanning motion 104 is much faster than the first scanning motion 102. The zigzag scan motion repeats the first scan motion 1 02 and the second scan motion 1 04 °. Therefore, the first scan motion 1 2 provides the second depolarization m ′ curtain 1 0 0 mainly Lighting. It is obvious to those skilled in the art that other scanning movements and sequences can also be used to illuminate the second depolarizing screen 100. In this third alternative embodiment 93, the spots are The number of unrelated speckle patterns is reduced. The four unrelated speckle patterns are caused by a combination of the second depolarizing screen Γ 〇 0 and the light path difference (provided by the speckle reduction structure 68). If the first laser 38 has a long coherence length, it is difficult or impractical for the optical path difference to be equal to or greater than the coherence length of the first laser 38. A fourth alternative embodiment of the present invention which considers a long coherence length is shown in FIG. 11. This fourth embodiment 105 is added to a piezoelectric converter 106 to the preferred embodiment. In this fourth alternative embodiment 105, the piezoelectric converter 106 is coupled to the fourth mirror 56. It is obvious to a person skilled in the art that the piezoelectric transducer 106 is coupled to the first, second or third mirror 50, 52 or 54, or the piezoelectric transducer 106 Is coupled to multiple mirrors. In this fourth alternative embodiment 105, the piezoelectric converter 106 moves the fourth mirror 56 so that the light path difference is changed by an amplitude. By changing the light path difference by a sufficient frequency, the third and fourth speckle patterns will be offset relative to the first and second speckle patterns, and the eye and intensity detectors are applicable to this paper. National standards ( CMS) A4 specification (210X297mm.) I.; A_w gutter (please read the precautions on the back before filling this page) -20- 499785 A7 B7 V. Description of the invention (18) {Please read the precautions on the back first Fill out this page again} It can be detected that the spots are reduced. This sufficient frequency is determined by an integration time of the eye or intensity detector. A first electronic signal 108 drives the piezoelectric converter 94. The first electronic signal 108 is preferably an oscillating voltage driven at the sufficient frequency. It is obvious to those skilled in the art that other electronic signals can also be used to drive the piezoelectric transducer 106, including a random wave signal. Preferably, the electronic signal 108 is a square wave signal. For ~ square waves, the amplitude is preferably an even multiple of half the wavelength of the first polarized laser output 46. Alternatively, the electronic signal 108 is a non-square wave signal, such as a sine wave. For non-square wave signals, the amplitude is preferably at least half the wavelength of the first polarized laser output 46. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A fifth alternative embodiment of the present invention is shown in FIG. 12. A fifth alternative embodiment 109 is added to a piezoelectric converter 106 to a third alternative embodiment 93. In this fifth alternative embodiment 109, the optical path difference does not have to be equal to or greater than the coherence length. In this fifth alternative embodiment 109, the piezoelectric converter 106 changes the optical path difference by an even multiple of half the wavelength of the first polarized laser output 46. In this fifth alternative embodiment 109, a second electronic signal 1 10 drives the piezoelectric converter 106. The second electronic signal 110 is a square wave voltage. It has a first voltage level, a second voltage level, and a square wave period. A difference between the first voltage level and the second voltage level 偏移 shifts the optical path difference by an even multiple of a half wavelength. The square wave period is a cycle of the first voltage level and the second voltage level. In this fifth alternative embodiment 109, the paper size of the first scanning movement is applicable. National Standard (CNS) A4 (210 X297 Public Manager) -21-499785 A7 B7 Intellectual Property Office Staff, Ministry of Economic Affairs Printed by the consumer cooperative V. Description of the invention (19) 102 and the first scanning movement 104 are defined as a scanning cycle. For a first scan period, the square wave voltage has the first voltage level. For a second scan period immediately after the first scan period, the square wave voltage has the second voltage level. For subsequent scans, the square wave period corresponds to two scan periods, so that for a third scan period, the square wave voltage has the first voltage level, and for a fourth scan period, S, The voltage has this second voltage level. Therefore, the third and fourth irrelevant speckle patterns are shifted relative to the first and second irrelevant speckle patterns in each scanning cycle pair. Speckle is reduced due to the combined effects of the depolarizing screen 100, the zigzag scanning motion, and the shift of the third and fourth unrelated speckle patterns. A sixth alternative embodiment of the present invention is shown in FIG. 13. A sixth alternative embodiment 1 1 1 adds a second laser 1 1 2 to the first laser 3 8, the polarized beam splitter 40, and the depolarizing screen 42. The first laser 38 is constructed to form the first polarized laser output 46 having an electric field directed to a p-polarization relative to the polarized beam splitter 66. The second laser output 1 1 2 is constructed to constitute the fifth polarized laser output 11 4 having an electric field oriented at an s-polarization with respect to the polarized beam splitter 66. The polarizing beam splitter 66 includes a multilayered dielectric that reflects s-polarization and transmits p-polarization. The first polarized laser output 4 6 passes through the polarized beam splitter 6 6. The fifth polarized laser output 114 is reflected by the polarized beam splitter θ Θ. In this sixth alternative embodiment 1 1 1, the first polarized laser (please read the precautions on the back before filling out this page)-installed ·, τ-threaded paper dimensions are applicable. National National Standards ( CNS) A4 specification (2 Η) X 297 mm) -22- 499785, Yi Yi 丨. ,, 丨 _ 丨, • Hermit. A7 B7 V. Description of the invention (20) Output 4 6 and the fifth polarization The laser output 1 1 4 is combined to form a combined laser output 1 1 5. The combined laser output 1 1 5 illuminates the depolarizing screen 4 2. Because the first laser 3 8 and the second laser 1 1 2 are non-coherent with each other, when the combined laser output 1 1 5 is irradiated on the depolarizing screen 4 2, four unrelated spots will be generated. pattern. It is obvious to those skilled in the art that the polarizing beam splitter 40 may be replaced with a device having a function similar to the multilayered dielectric of the polarizing beam splitter 66. A seventh alternative embodiment of the present invention is shown in FIG. 14. The seventh alternative embodiment 116 includes the first laser 38, the half-wave plate 80, the polarizing beam splitter 40, the first and second mirrors 50 and 52, and the depolarizing screen 42. The piezoelectric converter 106, the first electronic signal 108, and the first and second quarter-wave boards 1 1 8 and 1 2 0. The polarized beam splitter 40 divides the first polarized laser output 4 6 into sixth and seventh polarized laser outputs 1 2 2 and 1 2. 4 which have p-polarization and s-polarization, respectively. The first and second quarter-wave plates 1 1 8 and 1 2 0 have first and second optical axes, which respectively output 1 2 2 and 1 2 4 with respect to the sixth and seventh polarized lasers. The p-polarization and s-polarization are turned 45 degrees. The first and second quarter-wave boards 1 1 8. and 1 2 0 respectively convert the P-polarization and s-polarization of the sixth and seventh polarized laser outputs 1 2 2 and 1 2 4 to Circular polarization. The piezoelectric converter 106 driven by the first electronic signal 108 changes a sixth optical path length of the sixth polarized laser output 1 2 by an amount of change. The first electronic signal 108 is best to apply the Chinese National Standard (CNS) A4 specification (210X297 mm) at the paper size of the foot (please read the precautions on the back before filling this page).
、1T 經濟部智慧財產局員工消費合作社印製 -23- 499785 經濟·部智慧財產局員工消費合作社印製 A7 B7 五、發明説明（21) 夠頻率下被驅動的振盪電壓。 當該第六及第七偏振化的雷射輸出1 2 2及1 2 4回 到該第一及第二四分之一波板子1 0 8及1 2 0時，該第 一及第二四分之一波板子1 〇 8及1 2 0分別將當該第六 及第七偏振化的雷射輸出1 2 2及1 2 4轉變爲P -偏振 及s -偏振。該偏振光束分光器4 0反射該第六偏振化的 雷射輸出1 2 2並讓第七偏振化的雷射輸出1 2 4穿透過 ，因而形成一第八雷射輸出1 2 6其照射該去偏振螢幕 4 2。斑點被兩對不相關的斑點圖案所減少，它芒可藉由 將該第六光路徑長度改變振幅的大小而被進一步不相關。 本發明的一第八替代實施例被示於第1 5圖中。第八 替代實施例1 3 .0包括該第一及第二雷射3 8及1 1 2， 一雙折射晶體1 3 2，及該去偏振螢幕4 2。該第一雷射 3 8具有一第四直線偏振化的電場1 3 4。該第二雷射 1 1 2具有一第五直線偏振化的電場1 3 6。該雙折射晶 體1 3 2被定向使得該第一偏振化的雷射輸出4 6變成爲 在該雙折射晶體1 3 2內的一非常光線且該第五偏振化雷 射輸出1 1 4變成爲在該雙折射晶體1 3 2內的一尋常光 線。在離開該雙折射晶體1 3 2時，該第一及第五偏振化 的雷射.輸出46及114已結合形成該結合的雷射輸出 1 1 5。該結合的雷射輸出1 1 5照射該去偏振螢幕4 2 〇 第九替代實施例示於第1 6圖中。該第九替代實施例 1 4 0包括第一雷射3 8，一偏振旋轉器1 4 2，.及該去 本紙張尺度逍用中.國國家標準（CNS ) A4規格（210X297公釐·) I~.--.---·—裝------^訂-----^線 (請先閲讀背面之注意事項再填寫本頁) -24 499785 A7 B7 五、發明説明（22) 偏振螢幕4 2。在該第九替代實施例1 4 0中，該偏振旋 轉器1 4 2是被一第三電子訊號1 4 4所驅動。該偏振旋 轉器1 4 2旋轉該第一偏振化的雷射輸出4 6以形成一第 九雷射輸出1 4 6其具有一旋轉偏振。該第九雷射輸出照 射該去偏振螢幕4 2。具有該旋轉偏振的該第九雷射輸出 1 4 6產生四個不相關的斑點圖案。如果一旋轉頻率足夠 的話，則眼睛及強度偵測器將該四個不相關的斑點圖案平 均化，因此眼睛及前度偵測器可偵測到斑點被減少。該偏 振旋轉器1 4 2最好是一電子-光學偏振旋轉器，如.一液 晶偏振旋轉器，一 Pockel槽（cell )或一 Kerr槽（cell ) 。或者，該偏振旋轉器爲一半波板子其一機械.性地旋轉。 本發明的一第十替代實施例被示於第1 7圖中，該第 十替代實施例1 5 0包括該第一雷射3 8，該半波板子 8 0，該偏振光束分光器40，第一及第二鏡子5 0及 5 2,偏振螢幕4 2，及該第一及第二四分之一波板子. 1 1 8及1 2 0。該偏振光束分光器4 0將該第一偏振化 的雷射輸出4 6分成第十及第十一偏振化的雷射輸出 1 5 2及1 5 4其分別具有p —偏振及s -偏振。該偏振 光束分光器4 0透射該第十偏振化的雷射輸出1 5 2朝向 該第一四分之一波板子1 1 8。該偏振光束分光器4 0將 該第i--偏振化的雷射輸出1 5 4反射朝向該第二四分之 一波板子1 2 0。 該第一四分之一波板子1 1 8具有第一光軸其相對於 該第十偏振化的雷射輸出1 5 2的p偏振被轉4 5.度。該 本紙張尺度適用中國國家標準（CNS ) A4規格（210、乂297公釐) I-------·—1-- (請先閲讀背面之注意事項再填寫本頁) 訂 線 經濟部智慧財產局員工消費合作社印製 -25- 499785 A7 B7 五、發明説明（23) 第一四分之一波板子1 1 8將該第十偏振化的雷射輸出 1 5 2的P偏振轉換成圓形偏振。該第一鏡子5 0反射該 第十偏振化的雷射輸出1 5 2'。當該第十偏振化的雷射輸 出1 5 2回到該第一四分之一波板子1 1 8時，該第一四 分之一波板子將圓形偏振轉換成爲s -偏振。因此，該第 十偏振化的雷射輸出1 5 2沿著一第七光路徑長度從該偏 振光束分光反射器6 6前進至該第一鏡子5 0，然後回到 該偏振光束分光反射器6 6。該偏振光束分光器4 0然後 將該第十偏振化的雷射輸出1 5 2反射朝向該第二四.分之 一波板子12 0。 該第二四分之一波板子1 2 0具有第二光軸其相對於 該第十偏振化的雷射輸出1 5 2的s -偏振被轉4 5度。 該第二四分之一波板子1 2 0將該第十偏振化的雷射輸出 1 5 2的s . -偏振轉換成圓形偏振。該第二鏡子5 2反射 該第十偏振化的雷射輸出1 5 2。當該第十偏振化的雷射 輸出1 5 2回到該第一四分之一波板子1 2 0時，該第二 四分之一波板子將圓形偏振轉換成爲P -偏振。因此，該 第十偏振化的雷射輸出1 .5 2沿著一第八光路徑長度從該 偏振光束分光反射器6 6前進至該第二鏡子5 2，然後回 到該偏振光束分光反射器6 6。 該偏振光束分光器4透射該第十偏振化的雷射輸出 1 5 2 ,因而結合該第十偏振化的雷射輸出1 5 2及該第 十一偏振化的雷射輸出1 5 4以形成該第四.雷射輸出5 8 其具有介於該第十偏振化的雷射輸出1 5 2與該第十一偏 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐·) 111 _-==—& I == · 1 I--=== 1 - n H (請先閱讀背面之注意事項再填寫本頁) 訂 ▼線 經濟部智慧財產局員工消費合作社印製 -26- 499785 A7 B7 五、發明説明（24) 振化的雷射輸出1 5 4之間的光路徑差。該第七及第八光 路徑長度界定該光路徑差的光線導向器。最好是，該光路 徑差至少爲該相干長度。該第四雷射輸出5 8照射該去偏 振螢幕4 2，及該斑點因而被四個不相關的斑點圖案所減 少。 對於熟悉此技藝者而言很明顯的是，在第十替代實施 例1 5 0中，第一及第二四分之一波板子118及120 可藉由羅該第一鏡子5 0反射該第十偏振化的雷射輸出 1 5 2至該第二鏡子5 2及讓該第二鏡子5 2反射該第十 偏振化的雷射輸出1 5 2至該偏振光束分光反射器6 6而 被取消。 第一及第二試驗係使用與較佳實施例3 7相似的一第 一試驗安排來實施。在第一試驗中，該斑點減少結構6 8 並不存在。在第二試驗中，則有該斑點減少結構6 8。理 論上，該斑點減少結構6 8應將斑點減少0 ▲ 7 0 7 = 1 /( 2 ) 1 / 2的因數，因爲該斑點減少結構6 8將不相 關的斑點圖案數目加倍。在第一試驗中，對比爲5 6 · 8 %。在第二試驗中，對比爲4 2 . 2 %。這使得減少因數 爲0 · 7 4 3 ,這與0 · 7 0 7的理論値相近。 對於熟悉此技藝者而言很明顯的是，在不偏離由以下 的申請專利範圍所界定之本發明的範圍之下可對於該較佳 實施例作出其它不同的變化。 本紙張尺度適用中國國家標準（CNS ) A4規格（210 X297公釐) (請先閲讀背面之注意事項再填寫本頁) 1裝--- 訂-----^線 經濟部智慧財產局員工消費合作社印製 -271T Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -23- 499785 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (21) Oscillation voltage driven at sufficient frequency. When the sixth and seventh polarized laser outputs 1 2 2 and 1 2 4 return to the first and second quarter-wave boards 1 0 8 and 1 2 0, the first and second four The half-wave boards 1 0 and 1 2 0 respectively convert the laser outputs 1 2 2 and 1 2 4 that are the sixth and seventh polarizations to P-polarized and s-polarized. The polarized beam splitter 40 reflects the sixth polarized laser output 1 2 2 and passes the seventh polarized laser output 1 2 4 through, thereby forming an eighth laser output 1 2 6 which illuminates the Depolarized screen 4 2. The spots are reduced by two pairs of uncorrelated spots, which can be further uncorrelated by changing the amplitude of the sixth optical path length. An eighth alternative embodiment of the present invention is shown in FIG. 15. An eighth alternative embodiment 13.0 includes the first and second lasers 3 8 and 1 1 2, a birefringent crystal 1 3 2, and the depolarizing screen 4 2. The first laser 3 8 has a fourth linearly polarized electric field 1 3 4. The second laser 1 1 2 has a fifth linearly polarized electric field 1 3 6. The birefringent crystal 1 3 2 is oriented such that the first polarized laser output 4 6 becomes an extraordinary light in the birefringent crystal 1 3 2 and the fifth polarized laser output 1 1 4 becomes An ordinary light in the birefringent crystal 1 3 2. When leaving the birefringent crystal 1 32, the first and fifth polarized lasers. Outputs 46 and 114 have been combined to form the combined laser output 1 1 5. The combined laser output 1 1 5 illuminates the depolarizing screen 4 2 0. A ninth alternative embodiment is shown in FIG. 16. The ninth alternative embodiment 140 includes a first laser 38, a polarization rotator 142, and a paper size standard. National Standard (CNS) A4 (210X297 mm ·) I ~ .--.------- install ------ ^ order ----- ^ line (please read the precautions on the back before filling this page) -24 499785 A7 B7 V. Description of the invention ( 22) Polarized screen 4 2. In the ninth alternative embodiment 140, the polarization rotator 142 is driven by a third electronic signal 144. The polarization rotator 1 4 2 rotates the first polarized laser output 4 6 to form a ninth laser output 1 4 6 which has a rotating polarization. The ninth laser output illuminates the depolarizing screen 42. The ninth laser output 1 4 6 with the rotating polarization produces four unrelated speckle patterns. If a rotation frequency is sufficient, the eye and intensity detector averages the four irrelevant speckle patterns, so the eye and anterior detector can detect that the speckle is reduced. The polarization rotator 1 4 2 is preferably an electron-optical polarization rotator, such as a liquid crystal polarization rotator, a Pockel cell (cell) or a Kerr cell (cell). Alternatively, the polarization rotator is one of the half-wave plates which is mechanically rotated. A tenth alternative embodiment of the present invention is shown in FIG. 17. The tenth alternative embodiment 150 includes the first laser 38, the half-wave plate 80, and the polarizing beam splitter 40. The first and second mirrors 50 and 52, the polarizing screen 42, and the first and second quarter-wave boards. 1 1 8 and 1 2 0. The polarized beam splitter 40 divides the first polarized laser output 46 into tenth and eleventh polarized laser outputs 1 5 2 and 1 5 4 which have p-polarization and s-polarization, respectively. The polarized beam splitter 40 transmits the tenth polarized laser output 15 2 toward the first quarter wave plate 1 1 8. The polarized beam splitter 40 reflects the i-polarized laser output 15 4 toward the second quarter-wave plate 1 2 0. The first quarter-wave plate 1 1 8 has a first optical axis whose p polarization is turned 45 ° with respect to the tenth polarized laser output 1 5 2. This paper size is applicable to China National Standard (CNS) A4 specifications (210, 乂 297 mm) I ------- · —1-- (Please read the precautions on the back before filling this page) Printed by the Ministry of Intellectual Property Bureau Consumer Cooperatives -25- 499785 A7 B7 V. Description of Invention (23) The first quarter wave board 1 1 8 P polarization conversion of the tenth polarized laser output 1 5 2 Into circular polarization. The first mirror 50 reflects the tenth polarized laser output 15 2 '. When the tenth-polarized laser output 15 2 returns to the first quarter-wave plate 1 1 8, the first quarter-wave plate converts circular polarization to s-polarization. Therefore, the tenth polarized laser output 1 5 2 advances from the polarized beam splitter reflector 6 6 to the first mirror 50 along a seventh optical path length, and then returns to the polarized beam splitter reflector 6 6. The polarized beam splitter 40 then reflects the tenth polarized laser output 15 2 toward the second quarter-wave plate 12 0. The second quarter-wave plate 1 2 0 has a second optical axis whose s-polarization is turned 45 degrees with respect to the tenth polarized laser output 1 5 2. The second quarter-wave board 1 2 0 converts the s .-polarization of the tenth polarized laser output 15 2 into a circular polarization. The second mirror 5 2 reflects the tenth polarized laser output 1 5 2. When the tenth polarized laser output 15 2 returns to the first quarter wave plate 1 2 0, the second quarter wave plate converts circular polarization to P-polarization. Therefore, the tenth polarized laser output 1.5 2 proceeds along the eighth optical path length from the polarized beam splitter reflector 6 6 to the second mirror 5 2 and then returns to the polarized beam splitter reflector 6 6. The polarized beam splitter 4 transmits the tenth polarized laser output 1 5 2, and thus combines the tenth polarized laser output 1 5 2 and the eleventh polarized laser output 1 5 4 to form The fourth. Laser output 5 8 It has laser output 1 5 2 between the tenth polarization and the eleventh partial paper size application. National National Standard (CNS) A4 specification (210X297 mm · ) 111 _- == — & I == · 1 I-=== 1-n H (Please read the precautions on the back before filling out this page) Order ▼ Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -26- 499785 A7 B7 V. Description of the invention (24) The optical path difference between the oscillated laser output 1 5 4. The seventh and eighth light path lengths define the light guide with the light path difference. Preferably, the optical path difference is at least the coherence length. The fourth laser output 5 8 illuminates the depolarizing screen 42, and the spots are thus reduced by four unrelated spot patterns. It is obvious to those skilled in the art that in the tenth alternative embodiment 150, the first and second quarter-wave plates 118 and 120 can reflect the first mirror by the first mirror 50. The ten-polarized laser output 1 5 2 to the second mirror 52 and the second mirror 52 to reflect the tenth-polarized laser output 1 5 2 to the polarized beam splitter reflector 6 6 are cancelled. . The first and second tests were performed using a first test arrangement similar to the preferred embodiment 37. In the first experiment, the speckle reduction structure 6 8 was absent. In the second experiment, the speckle reduction structure 6 8 was present. In theory, the speckle reduction structure 6 8 should reduce the speckle by a factor of 0 ▲ 7 0 7 = 1 / (2) 1/2 because the speckle reduction structure 6 8 doubles the number of irrelevant speckle patterns. In the first test, the comparison was 56. 8%. In the second test, the comparison was 42.2%. This results in a reduction factor of 0 · 7 4 3, which is similar to the theoretical 値 of 0 · 7 0 7. It will be apparent to those skilled in the art that other different changes can be made to the preferred embodiment without departing from the scope of the invention as defined by the following patent application scope. This paper size applies to China National Standard (CNS) A4 (210 X297 mm) (Please read the precautions on the back before filling out this page) 1 Pack --- Order ------ ^ Line of Intellectual Property, Staff, Ministry of Economic Affairs Printed by Consumer Cooperatives-27